xref: /openbmc/linux/drivers/scsi/a3000.c (revision 0a94608f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/types.h>
3 #include <linux/mm.h>
4 #include <linux/ioport.h>
5 #include <linux/init.h>
6 #include <linux/slab.h>
7 #include <linux/spinlock.h>
8 #include <linux/interrupt.h>
9 #include <linux/platform_device.h>
10 #include <linux/module.h>
11 
12 #include <asm/page.h>
13 #include <asm/amigaints.h>
14 #include <asm/amigahw.h>
15 
16 #include <scsi/scsi.h>
17 #include <scsi/scsi_cmnd.h>
18 #include <scsi/scsi_device.h>
19 #include <scsi/scsi_eh.h>
20 #include <scsi/scsi_tcq.h>
21 #include "wd33c93.h"
22 #include "a3000.h"
23 
24 
25 struct a3000_hostdata {
26 	struct WD33C93_hostdata wh;
27 	struct a3000_scsiregs *regs;
28 };
29 
30 static irqreturn_t a3000_intr(int irq, void *data)
31 {
32 	struct Scsi_Host *instance = data;
33 	struct a3000_hostdata *hdata = shost_priv(instance);
34 	unsigned int status = hdata->regs->ISTR;
35 	unsigned long flags;
36 
37 	if (!(status & ISTR_INT_P))
38 		return IRQ_NONE;
39 	if (status & ISTR_INTS) {
40 		spin_lock_irqsave(instance->host_lock, flags);
41 		wd33c93_intr(instance);
42 		spin_unlock_irqrestore(instance->host_lock, flags);
43 		return IRQ_HANDLED;
44 	}
45 	pr_warn("Non-serviced A3000 SCSI-interrupt? ISTR = %02x\n", status);
46 	return IRQ_NONE;
47 }
48 
49 static int dma_setup(struct scsi_cmnd *cmd, int dir_in)
50 {
51 	struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(cmd);
52 	struct Scsi_Host *instance = cmd->device->host;
53 	struct a3000_hostdata *hdata = shost_priv(instance);
54 	struct WD33C93_hostdata *wh = &hdata->wh;
55 	struct a3000_scsiregs *regs = hdata->regs;
56 	unsigned short cntr = CNTR_PDMD | CNTR_INTEN;
57 	unsigned long addr = virt_to_bus(scsi_pointer->ptr);
58 
59 	/*
60 	 * if the physical address has the wrong alignment, or if
61 	 * physical address is bad, or if it is a write and at the
62 	 * end of a physical memory chunk, then allocate a bounce
63 	 * buffer
64 	 */
65 	if (addr & A3000_XFER_MASK) {
66 		wh->dma_bounce_len = (scsi_pointer->this_residual + 511) & ~0x1ff;
67 		wh->dma_bounce_buffer = kmalloc(wh->dma_bounce_len,
68 						GFP_KERNEL);
69 
70 		/* can't allocate memory; use PIO */
71 		if (!wh->dma_bounce_buffer) {
72 			wh->dma_bounce_len = 0;
73 			return 1;
74 		}
75 
76 		if (!dir_in) {
77 			/* copy to bounce buffer for a write */
78 			memcpy(wh->dma_bounce_buffer, scsi_pointer->ptr,
79 			       scsi_pointer->this_residual);
80 		}
81 
82 		addr = virt_to_bus(wh->dma_bounce_buffer);
83 	}
84 
85 	/* setup dma direction */
86 	if (!dir_in)
87 		cntr |= CNTR_DDIR;
88 
89 	/* remember direction */
90 	wh->dma_dir = dir_in;
91 
92 	regs->CNTR = cntr;
93 
94 	/* setup DMA *physical* address */
95 	regs->ACR = addr;
96 
97 	if (dir_in) {
98 		/* invalidate any cache */
99 		cache_clear(addr, scsi_pointer->this_residual);
100 	} else {
101 		/* push any dirty cache */
102 		cache_push(addr, scsi_pointer->this_residual);
103 	}
104 
105 	/* start DMA */
106 	mb();			/* make sure setup is completed */
107 	regs->ST_DMA = 1;
108 	mb();			/* make sure DMA has started before next IO */
109 
110 	/* return success */
111 	return 0;
112 }
113 
114 static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
115 		     int status)
116 {
117 	struct scsi_pointer *scsi_pointer = WD33C93_scsi_pointer(SCpnt);
118 	struct a3000_hostdata *hdata = shost_priv(instance);
119 	struct WD33C93_hostdata *wh = &hdata->wh;
120 	struct a3000_scsiregs *regs = hdata->regs;
121 
122 	/* disable SCSI interrupts */
123 	unsigned short cntr = CNTR_PDMD;
124 
125 	if (!wh->dma_dir)
126 		cntr |= CNTR_DDIR;
127 
128 	regs->CNTR = cntr;
129 	mb();			/* make sure CNTR is updated before next IO */
130 
131 	/* flush if we were reading */
132 	if (wh->dma_dir) {
133 		regs->FLUSH = 1;
134 		mb();		/* don't allow prefetch */
135 		while (!(regs->ISTR & ISTR_FE_FLG))
136 			barrier();
137 		mb();		/* no IO until FLUSH is done */
138 	}
139 
140 	/* clear a possible interrupt */
141 	/* I think that this CINT is only necessary if you are
142 	 * using the terminal count features.   HM 7 Mar 1994
143 	 */
144 	regs->CINT = 1;
145 
146 	/* stop DMA */
147 	regs->SP_DMA = 1;
148 	mb();			/* make sure DMA is stopped before next IO */
149 
150 	/* restore the CONTROL bits (minus the direction flag) */
151 	regs->CNTR = CNTR_PDMD | CNTR_INTEN;
152 	mb();			/* make sure CNTR is updated before next IO */
153 
154 	/* copy from a bounce buffer, if necessary */
155 	if (status && wh->dma_bounce_buffer) {
156 		if (SCpnt) {
157 			if (wh->dma_dir && SCpnt)
158 				memcpy(scsi_pointer->ptr, wh->dma_bounce_buffer,
159 				       scsi_pointer->this_residual);
160 			kfree(wh->dma_bounce_buffer);
161 			wh->dma_bounce_buffer = NULL;
162 			wh->dma_bounce_len = 0;
163 		} else {
164 			kfree(wh->dma_bounce_buffer);
165 			wh->dma_bounce_buffer = NULL;
166 			wh->dma_bounce_len = 0;
167 		}
168 	}
169 }
170 
171 static struct scsi_host_template amiga_a3000_scsi_template = {
172 	.module			= THIS_MODULE,
173 	.name			= "Amiga 3000 built-in SCSI",
174 	.show_info		= wd33c93_show_info,
175 	.write_info		= wd33c93_write_info,
176 	.proc_name		= "A3000",
177 	.queuecommand		= wd33c93_queuecommand,
178 	.eh_abort_handler	= wd33c93_abort,
179 	.eh_host_reset_handler	= wd33c93_host_reset,
180 	.can_queue		= CAN_QUEUE,
181 	.this_id		= 7,
182 	.sg_tablesize		= SG_ALL,
183 	.cmd_per_lun		= CMD_PER_LUN,
184 	.cmd_size		= sizeof(struct scsi_pointer),
185 };
186 
187 static int __init amiga_a3000_scsi_probe(struct platform_device *pdev)
188 {
189 	struct resource *res;
190 	struct Scsi_Host *instance;
191 	int error;
192 	struct a3000_scsiregs *regs;
193 	wd33c93_regs wdregs;
194 	struct a3000_hostdata *hdata;
195 
196 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
197 	if (!res)
198 		return -ENODEV;
199 
200 	if (!request_mem_region(res->start, resource_size(res), "wd33c93"))
201 		return -EBUSY;
202 
203 	instance = scsi_host_alloc(&amiga_a3000_scsi_template,
204 				   sizeof(struct a3000_hostdata));
205 	if (!instance) {
206 		error = -ENOMEM;
207 		goto fail_alloc;
208 	}
209 
210 	instance->irq = IRQ_AMIGA_PORTS;
211 
212 	regs = ZTWO_VADDR(res->start);
213 	regs->DAWR = DAWR_A3000;
214 
215 	wdregs.SASR = &regs->SASR;
216 	wdregs.SCMD = &regs->SCMD;
217 
218 	hdata = shost_priv(instance);
219 	hdata->wh.no_sync = 0xff;
220 	hdata->wh.fast = 0;
221 	hdata->wh.dma_mode = CTRL_DMA;
222 	hdata->regs = regs;
223 
224 	wd33c93_init(instance, wdregs, dma_setup, dma_stop, WD33C93_FS_12_15);
225 	error = request_irq(IRQ_AMIGA_PORTS, a3000_intr, IRQF_SHARED,
226 			    "A3000 SCSI", instance);
227 	if (error)
228 		goto fail_irq;
229 
230 	regs->CNTR = CNTR_PDMD | CNTR_INTEN;
231 
232 	error = scsi_add_host(instance, NULL);
233 	if (error)
234 		goto fail_host;
235 
236 	platform_set_drvdata(pdev, instance);
237 
238 	scsi_scan_host(instance);
239 	return 0;
240 
241 fail_host:
242 	free_irq(IRQ_AMIGA_PORTS, instance);
243 fail_irq:
244 	scsi_host_put(instance);
245 fail_alloc:
246 	release_mem_region(res->start, resource_size(res));
247 	return error;
248 }
249 
250 static int __exit amiga_a3000_scsi_remove(struct platform_device *pdev)
251 {
252 	struct Scsi_Host *instance = platform_get_drvdata(pdev);
253 	struct a3000_hostdata *hdata = shost_priv(instance);
254 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
255 
256 	hdata->regs->CNTR = 0;
257 	scsi_remove_host(instance);
258 	free_irq(IRQ_AMIGA_PORTS, instance);
259 	scsi_host_put(instance);
260 	release_mem_region(res->start, resource_size(res));
261 	return 0;
262 }
263 
264 static struct platform_driver amiga_a3000_scsi_driver = {
265 	.remove = __exit_p(amiga_a3000_scsi_remove),
266 	.driver   = {
267 		.name	= "amiga-a3000-scsi",
268 	},
269 };
270 
271 module_platform_driver_probe(amiga_a3000_scsi_driver, amiga_a3000_scsi_probe);
272 
273 MODULE_DESCRIPTION("Amiga 3000 built-in SCSI");
274 MODULE_LICENSE("GPL");
275 MODULE_ALIAS("platform:amiga-a3000-scsi");
276